Colorectal cancer screening (CRCS) decreases colorectal cancer mortality and incidence however, 40-60% of eligible adults are not screened at recommended intervals, and many have never had any type of CRCS. Screening failures occur from both lack of screening and breakdowns in follow-up of positive tests. Strategies for improving the uptake of CRCS typically focus on either patients or health care providers, without describing the infrastructure changes, or systems of support (SOS), that are required to implement and sustain these changes. We propose a two-part study using the Chronic Care Model to organize SOS. We will identify a cohort of Group Health patients aged 50 -75 years whose CRCS is not current according to national guidelines. In Part A: Subjects will be randomized to receive one of four interventions of stepwise increasing intensity of support: 1.Usual care (UC). 2.Automated support (UC+ mailed information, fecal occult cards (FOBT) and reminders, and access to a cancer screening hotline to discuss other screening options). S.Assisted support (UC+ automated + a medical assistant to record choice and assists patients in completing the choice via the resources already supplied or sending requests to the patient's physician). 4.Nurse care management support (UC + automated + assisted + a cancer screening nurse who manages patient care by clarifying patient CRCS intent, assessing procedural risk, ordering tests, and assists with completion of the action plan). In Part B: Patients with a positive FOBT or flexible sigmoidoscopy (colonoscopy needed) will be randomized to one of two follow-up intervention arms. A.UC (which at Group Health includes a registry and physician alerts) or B.Nurse care management (UC + cancer screening nurse who manages care after a positive test. Our study hypotheses are that: 1. increasing levels of SOS wil result in increasing CRCS rates and 2. care management by cancer screening nurses will increase follow-up rates after a positive test. The primary specific aims are: 1. To compare the effectiveness of each intervention condition on increasing CRCS rates 2. To compare the effectiveness of each intervention condition on follow-up after a positive screening test The secondary aims are: 3. To assess the effects of each intervention condition on participants'cognitive, affective, and social factors related to CRCS adherence and satisfaction with medical services 4. To compare utilization, costs, and incremental cost-effectiveness of each intervention condition